She said while there was little data available in Australia on unschooling, the 2014 parliamentary inquiry found home-schooled students out-performed mainstream school students across literacy and numeracy in all year levels — although the number of home-school students taking the NAPLAN test would have been around 10 per cent.

For home-schooled students who had returned to mainstream school, Dr English said she had seen evidence their performance in NAPLAN testing was still higher than mainstream-schooled students.

Dr English also referred to the Sudbury Valley democratic schools in the USA, which were free schools where students were left to decide what to do with their time and direct their own learning.

She said these students generally attended a college of their choice because they were able to demonstrate they could learn.

Parents are not trained professionals

Curtin University Associate Professor Eva Dobozy said that while parents were drawn to the idea that children can learn naturally and follow their passion, or that formal education may hinder their natural curiosity, a learning-centred approach had been adopted at all levels of the education system.

"These days formal education is play-based and children are allowed to follow their curiosity, and it is very much non-formal and informal in their learning," she said.

She said research from the colleges suggested they sought out unschooled students because they were able to manage their own learning, which translated to higher course retention rates for those colleges.

Associate Professor Dobozy is critical of unschooling for the reason that teachers are highly trained professionals.

"Parents very often do not have this trained background and may not always have the high level of interpersonal skills and attitudes, and the knowledge of child development that comes with teacher education," she said.

"There's always change and to technology, and digital literacy skills become part of the new curriculum.

"It's really important that children have great exposure to digital technologies and how to work with them and learn with them, and privacy issues and so forth.

"Schools spend a lot of money in ensuring that they have, not just the right technology, but also the right pedagogy to ensure that children can learn through synchronised online communication with each other."

Kids can 'learn anything they want to'

Natalie said she had not taught her children to walk, to speak or to crawl as babies but they learnt all those things themselves.

"By exposing them through reading to literacy and through singing [to language, rhythm, counting] it became a very natural evolution [to continue unschooling]," she said.